FTTP - Troubleshooting
FTTP ONT Troubleshooting
Light
Status
Meaning
What to do
POWER (right-hand light)
Green
Openreach fibre modem is on.
Check PON and LOS status below.
Off
Openreach fibre modem is off.
Check the mains plug is in.
PON and LOS (left-hand lights)
PON solid green
Fibre optic link to the exchange is working and recognises your Openreach fibre modem.
Check physical connection at both ends of the cable between the Openreach fibre modem and router. Try an alternative ethernet cable if the customer is having problems reaching the internet.
PON flashing and LOS off
Openreach fibre modem is communicating with BT exchange for verification.
Wait until light turns solid green.
PON off, or PON and LOS both flashing
Fibre optic link is not connected or there's a problem between your property and the exchange.
Check that the thin white fibre optic cable coming into your Openreach fibre modem is inserted and not damaged. Turn the Openreach fibre modem's power off, then back on and wait five minutes for the Openreach fibre modem to attempt to reconnect.
PORT1-PORT4
On (any)
Ethernet connection is normal between Openreach fibre modem and Hub (Port 1 is where engineer will install).
There may be a connection problem - check your router.
Blinking (any)
Data is being transmitted through the port.
There may be a connection problem - check your router.
Off (all)
Ethernet cable to modem is not inserted or broken.
Check physical connection at both ends of the cable. Try new cable if needed.
TEL 1-2
On (any)
The fibre home phone line is live on your modem.
Initially, you need to activate your fibre home phone line.
Blinking (any)
Fibre home phone line is not activated.
Wait until light turns solid green.
Off (all)
Fibre home phone line is not activated.
Check the mains cable is plugged in and the modem is switched on.
Optical
Green solid
Connected
Check physical connection at both ends of the cable between the Openreach modem and router. Try a new cable if needed.
FTTP Network Termination Equipment
For FTTP services an Optical Network Termination (ONT) installed at the customers premises for their modem to be connected to.
Openreach modem ports
- Optical: This hosts the fibre optic cable that comes from the exchange to your house.
- PORT 1: Here you plug in an Ethernet cable that runs to your BT Hub. Some modems have multiple ports.
- TEL 1: Digital voice customers can use this to plug in a telephone.
- BBU: This port attaches to the battery back-up unit, if there is one.
- DC: Depending on your modem, this connects to the power supply or the BBU unit
Types of Openreach modem
There are five different types of Openreach modem. There are slight variations in the way they look including the lights, but they all do the same job.
Huawei 1-port modem
This modem comes with a back-up battery Pack (BBU) in a white box, which enables your phone to continue to work after a power cut. The engineer will install on your wall. The flap protects the cables and the front door opens so you can reach the ports.
Huawei 4-port modem
This modem has four ports, you will probably only use ‘PORT 1’ to connect your Smart Hub.
ONT Types
These are made by Huawei or Nokia and examples of the models are shown below
